U.S. Pat. No. 6,053,371 discloses a finger-type pump dispenser for liquid products such as body lotions. A pump chamber includes a cylinder, and a piston slidable within the cylinder and having an outlet passage extending through the piston. A spring is disposed within the chamber to urge the piston to an extended position. An inlet opening at a lower end of the chamber receives product to be dispensed. An inlet valve ball cooperates with a valve seat at the inlet opening of the chamber to permit entry of product into the chamber as the piston is extended by the spring, but to prevent exit of product from the chamber through the inlet opening as the piston is manually depressed against the spring. An outlet valve ball is carried by the piston within the outlet passage to permit discharge of product from the chamber as the piston is manually depressed against the spring, but to prevent entry of air into the chamber through the outlet passage as the piston is extended by the spring. It is a general object of the present invention to provide improvements in construction of the inlet valve and/or the outlet valve in pump dispensers of this type.
The present invention embodies a number of different aspects, which may be used separately from or more preferably in combination with each other.
In accordance with a first aspect of the present invention, a pump dispenser for liquid products includes a pump chamber having a cylinder, and a piston slidable within the cylinder with an outlet passage extending through the piston. A spring within the chamber urges the piston to an extended position. An inlet opening is disposed at an end of the chamber for receiving product to be dispensed. An inlet check valve is positioned at the inlet opening to permit entry of product into the chamber as the piston is extended by the spring, but to prevent exit of product from the chamber through the inlet opening as the piston is depressed against the spring. An outlet check valve is carried by the piston within the outlet passage to permit discharge of product from the chamber through the piston outlet passage as the piston is depressed against the spring. The outlet check valve includes a concave valve body of flexible resilient construction opening away from the chamber and having an external periphery in radial surface-to-surface resilient sealing contact with an opposing inwardly radially facing wall surface of the outlet passage surrounding the valve.
A pump dispenser for liquid products in accordance with a second aspect of the invention includes a pump chamber with a cylinder, and a piston slidable within the cylinder and having an outlet passage extending through the piston. An inlet opening at an end of the chamber receives product to be dispensed, and a spring is disposed within the chamber urging the piston to an extended position. An inlet check valve at the inlet opening permits entry of product into the chamber as the piston is extended by the spring, but prevents exit of product from the chamber through the inlet opening as the piston is depressed against the spring. An outlet check valve is carried by the piston within the outlet passage to permit discharge of product from the chamber through the piston outlet passage as the piston is depressed against the spring. At least one of the inlet and outlet check valves is in the form of a valve cartridge assembly disposed in the outlet passage. The valve cartridge assembly includes a collar having a valve seat surface and a valve element captured within the collar for sealing engagement with the valve seat surface. In accordance with one embodiment of this aspect of the invention, the outlet check valve includes a concave outlet valve of flexible resilient construction that is molded into the collar. In another embodiment of this aspect of the invention, the outlet check valve comprises a valve ball that is captured within the collar and cooperates with a valve ball seat at one end of the collar.
In accordance with yet another aspect of the present invention, a pump dispenser for liquid products includes a pump chamber having a cylinder, and a piston slidable within the cylinder and having an outlet passage extending through the piston. An inlet opening at an end of the chamber receives product to be dispensed, and a spring within the chamber urges the piston to an extended position. An inlet check valve at the inlet opening permits entry of product into the chamber as the piston is extended by the spring, but prevents exit of product from the chamber through the inlet opening as the piston is depressed against the spring. An outlet check valve is carried by the piston within the outlet passage to permit discharge of product from the chamber through the piston outlet passage as the piston is depressed against the spring. The inlet valve includes a concave valve body of flexible resilient construction opening into the chamber and having a periphery in radial surface-to-surface resilient sealing contact with an opposing radially inwardly facing surface of the inlet opening.
A pump dispenser for liquid products in accordance with another aspect of the invention includes a pump chamber with a cylinder, and a piston slidable within the cylinder and having an outlet passage extending through the piston. An inlet opening at an end of the chamber receives product to be dispensed, and a spring within the chamber urges the piston to an extended position. An inlet check valve at the inlet opening permits entry of product into the chamber through the inlet opening as the piston is extended by the spring, but prevents exit of product from the chamber through the inlet opening as the piston is depressed against the spring. An outlet check valve is carried by the piston within the outlet passage to permit discharge of product from the chamber through the piston outlet passage as the piston is depressed against the spring. The outlet check valve is of flexible resilient construction and is molded onto the body of the piston.
A pump dispenser for liquid products in accordance with a further aspect of the invention includes a pump chamber having a cylinder, and a piston slidable within the cylinder and having an outlet passage extending through the piston. An inlet opening at an end of the chamber receives product to be dispensed, and a spring within the chamber urges the piston to an extended position. An inlet check valve at the inlet opening permits entry of product into the chamber through the inlet opening as the piston is extended by the spring, but prevents exit of product from the chamber through the inlet opening as the piston is depressed the spring. An outlet check valve is carried by the piston within the outlet passage to permit discharge of product from the chamber through the piston outlet passage as the piston is depressed against the spring. The inlet valve includes a valve ball and a valve seat at the inlet opening. The outlet valve is of flexible resilient construction, and has a finger extending into the chamber for engaging the inlet valve ball and holding the inlet valve ball against the seat in a fully depressed position of the piston against the spring.
A pump dispenser for liquid products in accordance with another aspect of the invention includes a pump chamber with a cylinder, and a piston slidable within the cylinder and having an outlet passage extending the piston. An inlet opening at an end of the chamber receives product to be dispensed, and a spring within the chamber urges the piston to an extended position. An inlet check valve at the inlet opening permits entry of product into the chamber through the inlet opening as the piston is extended by the spring, but prevents exit of product from the chamber through the inlet opening as the piston is depressed against the spring. An outlet check valve is carried by the piston within the outlet passage to permit discharge of product from the chamber through the piston outlet passage as the piston is depressed against the spring. The outlet valve includes a collar for surrounding the inlet valve ball in the fully depressed position of the piston against the spring, both to hold the valve ball in position against its seat and to reduce the open volume of the chamber.